Chapter 10, Problem 30RQE

Program Plan Intro

“atof” function:

In C++, the predefined function “atof” is used to convert a string value into a double-precision floating point value; it passes a string literal or character array as an argument and it converts the received value into a double type value; it takes only one parameter as an argument.

• If the argument value contains nonconvertible contents combined with the integer value then the values will be ignored while converting.
• In same way, the function will return “0” when the values can’t be able to convert into double data type.

Syntax:

Syntax for the “atof” function is as follows:

double atof (const char* n);

In the above statement,

• “double” represents the return type of the function.
• “atof” represents the name of the function.
• “const char*” represents the data type of the passing argument.
• “n” is a string variable which is required to be converted.

Example:

The example for the “atof” function is as follows:

//change the string literal to a double value.

double n = atof ("1258.11E-14 ");

In the above line, the string literal “1258.11E-14” is passed as an argument to “atof” and it returns the converted value that is “1.25811e-11”.